The technical area involved in this invention is that of static digital recorders capable of recording analog parameters and intended to function in severe recording conditions (intense accelerations, high compression of air in front of moving objects, vibrations, extreme temperatures, high altitude or hyperbaria).
Magnetic accident recorders mounted on aircraft, called "black boxes" or "crash detectors", are alredy well-known. Some record data in analog form, and other in digital form.
One drawback encountered in these systems is the inability to record parameters at the moment of the accident itself, because the magnetic recorder stops working at the moment when the accident causes the intense accelerations.
The same thing happens with electro-magnetic phenomena detectors using entirely digital recorders with static memory. There the data is pre-processed by several microprocessors. This type of system was not designed as an accident recorder as such. It is not designed to operate in a rapidly changing dynamic shock or impact environment.
One such recorder is described in the periodical "Safe" (Vol. 14 No. 1, p. 13 to 20, 1984). This system is intended to be mounted on an anthropomorphic dummy used for set ejection testing. It allows recording of numerous parameters (16, 48 or 64) but requires one or more 16 input multiplexers. The sampling interval is at most 2,000 HZ, and the system has the drawback of not allowing for simultaneous measurement of several parameters. Finally, recording is not automatic since it requires the presence of an external electrical signal. In addition, this system is not designed for complete recording of the status of the parameters before, that is to say under completely normal conditions, during and after the accident. In fact, it is activated externally at an arbitrarily chosen moment when the parameters begin to vary abnormally or practically at the moment of ejection.